Are there rules for how loud the horns have to be? Let's see if they can safely be reduced in decibel level so that they do not disturb so many people so much. I bet that the TGV in France does not make so much noise and hence has better support among the public.
There sure are rules :
CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF
TRANSPORTATION
PART 229_RAILROAD LOCOMOTIVE SAFETY STANDARDS--Table of Contents
Subpart C_Safety Requirements
Sec. 229.129 Locomotive horn.
(a) Each lead locomotive shall be equipped with a locomotive horn
that produces a minimum sound level of 96 dB(A) and a maximum sound
level of 110 dB(A) at 100 feet forward of the locomotive in its
direction of travel. The locomotive horn shall be arranged so that it
can be conveniently operated from the engineer's usual position during
operation of the locomotive.
(b)(1) Each locomotive built on or after September 18, 2006 shall be
tested in accordance with this section to ensure that the horn installed
on such locomotive is in compliance with paragraph (a) of this section.
Locomotives built on or after September 18, 2006 may, however, be tested
in accordance with an acceptance sampling scheme such that there is a
probability of .05 or less of rejecting a lot with a proportion of
defectives equal to an AQL of 1% or less, as set forth in 7 CFR part 43.
(2) Each locomotive built before September 18, 2006 shall be tested
in accordance with this section before June 24, 2010 to ensure that the
horn installed on such locomotive is in compliance with paragraph (a) of
this section.
(3) Each remanufactured locomotive, as determined pursuant to Sec.
229.5 of this part, shall be tested in accordance with this section to
ensure that the horn installed on such locomotive is in compliance with
paragraph (a).
(4)(i) Except as provided in paragraph (b)(4)(ii) of this section,
each locomotive equipped with a replacement locomotive horn shall be
tested, in accordance with paragraph © of this section, before the
next two annual tests required by Sec. 229.27 of this part are
completed.
(ii) Locomotives that have already been tested individually or
through acceptance sampling, in accordance with paragraphs (b)(1),
(b)(2), or (b)(3) of this section, shall not be required to undergo
sound level testing when equipped with a replacement locomotive horn,
provided the replacement locomotive horn is of the same model as the
locomotive horn that was replaced and the mounting location and type of
mounting are the same.
© Testing of the locomotive horn sound level shall be in
accordance with the following requirements:
(1) A properly calibrated sound level meter shall be used that, at a
minimum, complies with the requirements of International
Electrotechnical Commission (IEC) Standard 61672-1 (2002-05) for a Class
2 instrument.
(2) An acoustic calibrator shall be used that, at a minimum,
complies with the requirements of IEC standard 60942 (1997-11) for a
Class 2 instrument.
(3) The manufacturer's instructions pertaining to mounting and
orienting the microphone; positioning of the observer; and periodic
factory recalibration shall be followed.
(4) A microphone windscreen shall be used and tripods or similar
microphone mountings shall be used that minimize
[[Page 441]]
interference with the sound being measured.
(5) The test site shall be free of large reflective structures, such
as barriers, hills, billboards, tractor trailers or other large
vehicles, locomotives or rail cars on adjacent tracks, bridges or
buildings, within 200 feet to the front and sides of the locomotive. The
locomotive shall be positioned on straight, level track.
(6) Measurements shall be taken only when ambient air temperature is
between 32 degrees and 104 degrees Fahrenheit inclusively; relative
humidity is between 20 percent and 95 percent inclusively; wind velocity
is not more than 12 miles per hour and there is no precipitation.
(7) With the exception of cab-mounted or low-mounted horns, the
microphone shall be located 100 feet forward of the front knuckle of the
locomotive, 15 feet above the top of the rail, at an angle no greater
than 20 degrees from the center line of the track, and oriented with
respect to the sound source according to the manufacturer's
recommendations. For cab-mounted and low-mounted horns, the microphone
shall be located 100 feet forward of the front knuckle of the
locomotive, four feet above the top of the rail, at an angle no greater
than 20 degrees from the center line of the track, and oriented with
respect to the sound source according to the manufacturer's
recommendations. The observer shall not stand between the microphone and
the horn.
(8) Background noise shall be minimal: the sound level at the test
site immediately before and after each horn sounding event shall be at
least 10 dB(A) below the level measured during the horn sounding.
(9) Measurement procedures. The sound level meter shall be set for
A-weighting with slow exponential response and shall be calibrated with
the acoustic calibrator immediately before and after compliance tests.
Any change in the before and after calibration levels shall be less than
0.5 dB. After the output from the locomotive horn system has reached a
stable level, the A-weighted equivalent sound level (slow response) for
a 10-second duration (LAeq, 10s) shall be obtained either directly using
an integrating-averaging sound level meter, or recorded once per second
and calculated indirectly. The arithmetic-average of a series of at
least six such 10-second duration readings shall be used to determine
compliance. The standard deviation of the readings shall be less than
1.5 dB.
(10) Written reports of locomotive horn testing required by this
part shall be made and shall reflect horn type; the date, place, and
manner of testing; and sound level measurements. These reports, which
shall be signed by the person who performs the test, shall be retained
by the railroad, at a location of its choice, until a subsequent
locomotive horn test is completed and shall be made available, upon
request, to FRA as provided by 49 U.S.C. 20107.
(d) This section does not apply to locomotives of rapid transit
operations which are otherwise subject to this part.
[71 FR 47666, Aug. 17, 2006]